He made his debut on 20 August 2014 in the second round of the Scottish Challenge Cup away to Livingston, replacing Gary Oliver in the 56th minute of a 4–1 loss.[3] On 26 October, he made his professional debut in the Scottish Championship, replacing Billy King for the final three minutes of a 1–1 Edinburgh derby draw with Hibernian at Easter Road.[4] On 5 May 2015, Buchanan signed a new two-year contract.[5] Buchanan eventually left the club at the end of the 2016–17 season, following the end of his contract.[6]
Loan moves
Buchanan was loaned to fellow Scottish Championship team Cowdenbeath on 16 January 2015,[7] playing 10 games without scoring,[8] as the season ended with relegation.
He returned to Cowdenbeath, now of Scottish League One, on 7 August,[9] and his loan ended at the start of November 2015.[10]
In November 2016, Buchanan joined Brechin City on a one-month emergency loan deal, in a bid to strengthen their squad.[11] On 31 January 2017, Buchanan joined Cowdenbeath for his third spell on loan at the Fife club, this time in Scottish League Two, until the end of the season.[12]
Cowdenbeath
After leaving Hearts, Buchanan joined Cowdenbeath on 3 July 2017 for his fourth spell with the club, this time on a permanent contract. He left the club at the end of the 2021-22 season following Cowdenbeath's relegation from the Football League.